"Star-crossed" or "star-crossed lovers" is a phrase describing a pair of lovers whose relationship is often thwarted by outside forces. The term encompasses other meanings, but originally means the pairing is being "thwarted by a malign star" or that the stars are working against the relationship. Astrological in origin, the phrase stems from the belief that the positions of the stars ruled over people's fates, and is best known from the play Romeo and Juliet by the Elizabethan playwright William Shakespeare. Such pairings are often said to be doomed from the start.
It also refers to destiny ["This isn't just random, this is destiny"(1.21 Petrelli).] and the inevitability of the two characters' paths crossing.